#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<algorithm>
using namespace std;
int integerBreak(int n) {
	int dp[60] = { 0 };
	dp[1] = 0;
	dp[2] = 1;
	for (int i = 3; i <= n; i++) {
		for (int j = 1; j <= i; j++) {
			dp[i] = max(max(j * (i - j), j * dp[i - j]), dp[i]);
		}
	}
	return dp[n];
}
int main()
{
	int n;
	cin >> n;
	cout << integerBreak(n);
	return 0;
}